EP3059644A1 - Portable device and method for determining and displaying a subjective duration - Google Patents

Abstract

Watch or other portable device on the body for determining and displaying a perceived subjective duration by a user, comprising:
one or more sensors generating at least one measurement signal,
an indicator for representing a duration;
a processor processing said measurement signal and controlling said indicator,
a computer memory storing a computer module executable by said processor for controlling said indicator to indicate the subjective duration of a time interval, such that said subjective duration is longer than the effective duration of said interval when said user has the impression that time elapses slowly during said interval, and shorter than the effective duration of this interval when said user has the impression that time runs rapidly during said interval,
said computer module being based on an automatic learning system for determining said subjective duration on the basis of said at least one measurement signal.

Description

Technical area

The present invention relates to a device and a method for determining and displaying a perceived subjective duration by a user.

State of the art

Conventional watchmaking allows extremely precise measurement of absolute time, or objective time, counted in seconds or multiples of the second. It's a collective time.

The present invention, however, relates to the measurement of subjective time, or time felt, that is to say, the evaluation of the time perceived by an individual and which may be different from the objective time. It is an individual and personal time.

It is well known that the perception of the course of time can be variable; sometimes, time seems to pass very quickly whereas at other times it flows much more slowly.

According to different neurological studies, the perception of the time-flow rate does not appear to be associated with a particular sensory area of the brain, but derives from a highly distributed system involving portions of the cerebral cortex, cerebellum, and lymph nodes. base including, even heart, tonsils or other organs. Different systems are responsible for the circadian (or daily) rhythm and the measurement of shorter durations during the day. The coexistence of several internal biological clocks is likely and seems to be proven by recent studies.

Subjective temporal perception is sometimes surprisingly precise. For example, a human is able to distinguish the order of two events spaced by only 20 milliseconds. Many people are able to wake up each morning at a specific time, for example exactly one minute before their alarm rings, even without external stimuli. The subjective perception of the duration of certain events may, however, be unclear; for example, it is often difficult to remember whether an event occurred five years ago or ten years ago. Without a clock, it is also very difficult to evaluate the duration of a discussion, a game or a holiday period for example.

The synchronization between objective time and subjective time, or on the contrary perceptive asymmetry, is the result of many endogenous and exogenous factors. It is well known that the subjective perception of the speed of time is affected by different external sensory stimuli, such as visual, auditory, tactile stimuli, and so on. The human sensory system associates these different stimuli with other events to place them on a temporal scale. For example, the perception of changes in ambient light during the day has a direct influence on the circadian cycle, as travelers who are subject to jet lag know well.

We also observe that physiological parameters internal to the person affect his perception of time. The perception of time seems to accelerate when body temperature rises, and slow down as the body cools.

It is also known that a state of stress can introduce hypersensitivity to emotional and environmental stimuli, with the ability to discern and process more information per unit of time, and thus frequently a perception of slowed time. Some people subjected to extreme stress, for example in the event of an accident, say "a second lasted as a year". Different research has also shown that time seems to slow down when people feel a threat or a dangerous situation, for example during a vertiginous dive. The same sensation of time deceleration occurs during unpredictable events.

Emotions or states of relaxation, relaxation, joy, comfort, etc., also modify the subjective perception of time. Research with students watching anxious movie footage revealed that these students often overestimate the duration of the scenes. Some biologists believe that this illusion would be a defense mechanism involving the tonsils and allowing the person in a state of anxiety to slow down his internal clock in order to be able to make more decisions in less time (increase the temporal resolution).

The perception of time can be affected by many illusions or perceptual filters, including the Kappa effect. This effect leads people to overestimate a duration between two stimuli when the spatial distance between these stimuli is important, and to underestimate the same duration when the spatial distance is lower. For example, a traveler who makes two trips of the same duration but of different lengths will tend to find that the most distant trip has lasted longer than the short trip of the same duration.

The age of the person also influences his perception of time; as we age, we tend to underestimate the duration of events. Differences in assessment of duration of nearly 20% were observed between a first group of subjects between 19 and 24 years and a second group between 60 and 80 years in charge of evaluating a duration of time. Some also think that a child's mental activity is permanently higher than that of an adult, because a child is constantly discovering new situations for him and thus creates more memories and more emotions than a child. adult subject to the same stimuli. As a result, the subjective perception of the duration of an equivalent period decreases with age. The subjective duration is also related to "available storage space" and retention memory capacity.

The body does not seem to react to exogenous or endogenous stimuli by changing the perception of time; it seems that it itself emits signals of physiological changes when this perception is modified and the body organizes and adapts temporality. For example, it seems that a disturbed temporal sensation, as is observed for example during time differences, experience of lives in caves, etc., creates in itself stress signals, for example stress hormones, changes in the respiratory and / or cardiac rhythm, sweating, changes in body temperature, etc.

The evaluation of subjective time periods, which can be real, symbolic and imaginary, is important for many applications. Watch brands capable of such measures could be distinguished from the competition by displaying additional information, both poetic and informative. Meaningful industrial objects could thus be realized.

Users are interested in obtaining a quantified measure of perceived perception, and thus measure for example if their workday has passed more or less quickly. Conversely, employers concerned with the well-being of their employees could measure their perception of time spent at work, and take this into account to offer everyone a position in the organization that offers them an optimal flow of time. . Retrospective consideration of the time experienced provides the user with the opportunity to more accurately evaluate his or her prospective time to plan future activities. For example, a user might determine that he needs a relatively constant number of subjective hours to perform a given intellectual task, but of varying objective duration. The display of this new measure would facilitate the passage from a prescribed time to a compound time.

Medical, therapeutic and psychological applications would also benefit from such a measure of subjective time.

Various solutions have therefore been proposed in the prior art for determining subjective time periods. US6304519 describes a device for comparing the real time that has elapsed since an event with the subjective time perceived by the user, and for displaying the deviation. The subjective time is determined on the basis of data entered by the user, who can for example indicate himself whether he performs a boring activity or an activity during which the time runs out quickly or which requires a greater intellectual involvement. The device makes it possible to display the deviation between the real time and the perceived time, and to display these data in relation to biological parameters such as the body temperature of the user, his heart rate, blood pressure or his metabolism. This device therefore imperatively requires the active participation of the user who must indicate himself the type of activity in which he is engaged or his perception as to the passage of time. Such a manual indication is binding, and based on subjective evaluations that do not allow to easily compare the results of several users.

US4630935 describes another instrument for displaying felt durations evaluated on the basis of the number of activations of a manual actuator.

WO2007 / 107900A2 describes a watch with a pointer for displaying the degree of "coolness" of a user during a past time. This degree of coolness is determined by physiological parameters such as heart rate, body temperature, movement, skin resistance or muscle activity. This document does not explain the relationship between the physiological parameters measured and the degree of "coolness" indicated. Nor is there any relationship between the degree of coolness and the speed of time.

Although it is understood that the perceived time is affected by measurable physical parameters, or that it leads to measurable physiological responses, the relationship between the different measurable parameters and the perceived duration is unknown. There is therefore no no known analytical methods for determining a subjective duration from a set of physical or chemical quantities.

Brief summary of the invention

An object of the present invention is therefore to provide a portable device capable of determining a subjective duration felt by a user more reliably than known devices.

• un ou plusieurs capteurs générant au moins un signal de mesure,
• un indicateur permettant de représenter une durée ;
• un processeur traitant ledit signal de mesure et commandant ledit indicateur,
• une mémoire informatique stockant un module informatique exécutable par ledit processeur afin de commander ledit indicateur pour indiquer la durée subjective d'un intervalle temporel, en sorte que ladite durée subjective soit plus longue que la durée effective de cet intervalle lorsque ledit utilisateur a l'impression que le temps s'écoule lentement pendant ledit intervalle, et plus courte que la durée effective de cet intervalle lorsque ledit utilisateur a l'impression que le temps s'écoule rapidement pendant ledit intervalle,
• ledit module informatique étant basé sur un système d'apprentissage automatique afin de déterminer ladite durée subjective sur la base dudit au moins un signal de mesure.

According to the invention, these objects are achieved in particular by means of a portable device on the body for determining and displaying a subjective duration perceived by a user, comprising:

• one or more sensors generating at least one measurement signal,
• an indicator for representing a duration;
• a processor processing said measurement signal and controlling said indicator,
• a computer memory storing a computer module executable by said processor for controlling said indicator to indicate the subjective duration of a time interval, such that said subjective duration is longer than the effective duration of said interval when said user has the impression that time elapses slowly during said interval, and shorter than the effective duration of this interval when said user has the impression that time runs rapidly during said interval,
• said computer module being based on an automatic learning system for determining said subjective duration on the basis of said at least one measurement signal.

In one embodiment, the indicator may also indicate a degree of satisfaction associated with the durations felt by the user. The indicator can for example indicate whether an acceleration of the temporal perception constitutes a satisfactory experience for the user, or on the contrary a stress.

By "portable device on the body" means devices also often referred to as "wearable device". It is therefore devices intended to be worn continuously or almost continuously close to the body of the user, without preventing him from going about his normal business. These devices are portable on the body without using one's hands. Examples of wearable devices on the body include, for example, wristwatches, smart glasses, sensor wristbands, smart clothing, smart jewelry, etc.

The measured duration can be entirely in the past. It can begin in the past and end in the present moment. If the duration is brief, the indicator indicates in each instant a speed of flow of subjective time at the present time (or during the brief period preceding the present moment).

The machine learning system can be based for example on a machine learning algorithm. It can use for example a self-learning classifier, for example a neural network, a support vector machine network (Support Vector Machines) and / or a hidden Markov model.

The use of an automatic learning system makes it possible to determine a subjective duration from various measurement signals, even without knowing the analytical relationship between the value of these signals and the perceived duration.

The machine learning system can be supervised, for example using a retropertinence loop, or unsupervised.

The machine learning system can be driven individually by each user. The subjective time displayed is thus clean and individual to each user.

The machine learning system can be trained for multiple users from training data from a body of users, for example with subjective duration indications provided by a corpus of several users. This allows more training data to be available more quickly, thus speeding up the training process.

It is thus possible to train a system universally for several users. It is possible to improve this initial universal training by adapting it to the perception of each individual user, or sub-groups of users.

The displayed subjective duration can be fully inscribed in the past. The device then displays the subjective duration of a completed interval, in the manner of a chronograph that displays the duration of a completed race.

The time interval for which the subjective duration is desired can begin in the past and end at the present time, so that the subjective duration indicator indicates the instantaneous feeling of the time flow rate.

Different sensors may be employed to determine a subjective duration with the device of the invention. The role of each measure in the perception of subjective duration does not need to be known a priori; the machine learning system determines this role automatically. However, it is desirable to reduce the number of sensors and measurement signals, both in order to reduce the cost of the device, its size, its power consumption, and to make the classification of measurement signals faster and more robust. renouncing the least relevant measurement signals.

One or more sensors can measure exogenous parameters to the user, for example environmental parameters, such as ambient temperature, brightness, etc., or external stimuli, for example, light stimuli, acoustic stimuli, tactile stimuli, etc.

One or more sensors can measure endogenous parameters of the user, for example his body temperature, his heart rate, his blood pressure, the resistivity of the skin, the rate of sweating, the rate of various hormones or proteins on the skin, and / or the elasticity of the skin.

The machine learning system can also use parameters introduced by the user, for example his age, and / or taken from his electronic calendar, to determine a subjective duration felt.

Brief description of the figures

• La figure 1 illustre une vue schématique d'un dispositif portable sur le corps selon l'invention.
• La figure 2 est un schéma-bloc d'un dispositif portable sur le corps selon l'invention.

Examples of implementation of the invention are indicated in the description illustrated by the appended figures in which:

• The figure 1 illustrates a schematic view of a portable device on the body according to the invention.
• The figure 2 is a block diagram of a portable device on the body according to the invention.

Example (s) of embodiment of the invention

The figure 1 schematically illustrates a portable device 1 according to the invention, here in the form of a watch. A similar device could be integrated in a jewel, a textile such as a shirt or glove for example, a bracelet, a belt, a combination of several of these devices, etc.

• Un capteur inertiel, par exemple un accéléromètre triaxial et/ou un gyroscope, afin de mesurer les déplacements de l'utilisateur ou d'une partie du corps de l'utilisateur. Une analyse de ces mouvements permet par exemple de déterminer l'activité à laquelle se livre l'utilisateur, ou de classer cette activité parmi des groupes d'activités. Il est par exemple possible de déterminer si l'utilisateur dort, marche, ou effectue un travail de bureau par exemple. L'utilisation d'un ou plusieurs capteurs inertiels permet aussi de déterminer la posture de l'utilisateur (assis, debout, couché), son activité ou des tremblements ou gestes nerveux caractéristiques par exemple. Le capteur inertiel peut être monté dans la montre, ou sur une autre partie du corps.
• Un récepteur de géolocalisation, par exemple un récepteur GPS, afin de déterminer l'emplacement de l'utilisateur, sa vitesse de déplacement, ou le moyen de déplacement employé. Ce récepteur de géolocalisation, et/ou le capteur inertiel, peut être utilisé pour déterminer la distance parcourue par l'utilisateur lors d'un déplacement ou entre deux stimuli, et pour évaluer ainsi l'influence de l'effet Kappa mentionné plus haut, en augmentant la durée du temps ressenti lors de déplacements de grande amplitude.
• Un capteur de température pour mesurer la température corporelle de l'utilisateur. La température corporelle peut en effet être un indicateur de l'activité physique et du stress de l'utilisateur.
• Un capteur de rythme cardiaque pour mesurer le pouls de l'utilisateur. Le rythme cardiaque peut en effet être un indicateur de l'activité physique et du stress de l'utilisateur.
• Un capteur permettant de mesurer un signal électrique à travers la peau de l'utilisateur, par exemple afin de mesurer la résistivité ou la capacitance de la peau, et donc son taux d'humidité par exemple. La sudation peut en effet être un indicateur de l'activité physique et du stress de l'utilisateur.
• Un capteur capable d'analyser la sueur de l'utilisateur, par exemple afin de mesurer la quantité de sueur ou sa composition, par exemple le taux de glycémie et/ou la présence d'hormones ou de protéines indicatrices du stress telle que la cortisone, l'adrénaline, la noradrénaline, la dopamine ou d'autres hormones ou protéines. Ce capteur peut être basé par exemple sur une plaquette microfluidique capable d'apporter par capillarité des échantillons de sueur sur des récepteurs.
• Un capteur mesurant le taux de testostérone sur la peau de l'utilisateur, comme indicateur d'activité.
• Un ou plusieurs capteurs environnementaux pour mesurer l'heure actuelle, la date actuelle, la température ambiante et/ou l'humidité ambiante et/ou la luminosité ambiante et/ou le niveau sonore ambiant. Il est aussi possible par exemple de distinguer entre différents types de signaux sonores afin de reconnaitre par exemple une discussion amicale ou une dispute, un bruit stressant, etc.
• Un module récupérant des données depuis l'agenda électronique et/ou depuis des réseaux sociaux de l'utilisateur, par exemple afin de déterminer à quelles activités se livre l'utilisateur à différents moments.
• Un capteur d'activité cérébrale, par exemple un détecteur d'électroencéphalogramme, capable par exemple de distinguer si le cerveau produit essentiellement des ondes α hautement périodiques, indiquant une activité cérébrale réduite, ou des ondes β aléatoires, indiquant une activité cérébrale plus intense.

The device comprises several sensors 2 for measuring exogenous parameters, for example physical quantities environmental and / or endogenous physical quantities of the user. One or more of the following sensors may be provided:

• An inertial sensor, for example a triaxial accelerometer and / or a gyroscope, for measuring the movements of the user or a part of the body of the user. An analysis of these movements makes it possible, for example, to determine the activity that the user engages in, or to classify this activity among groups of activities. For example, it is possible to determine whether the user is sleeping, walking, or doing office work, for example. The use of one or more inertial sensors also makes it possible to determine the posture of the user (sitting, standing, lying down), his activity or tremors or characteristic nervous gestures for example. The inertial sensor can be mounted in the watch, or on another part of the body.
• A geolocation receiver, for example a GPS receiver, for determining the user's location, speed of movement, or moving means employed. This geolocation receiver, and / or the inertial sensor, can be used to determine the distance traveled by the user during a movement or between two stimuli, and to thus evaluate the influence of the Kappa effect mentioned above, by increasing the duration of the time felt during large amplitude movements.
• A temperature sensor to measure the body temperature of the user. Body temperature can indeed be an indicator of the physical activity and stress of the user.
• A heart rate sensor to measure the user's pulse. The heart rate can indeed be an indicator of the physical activity and stress of the user.
• A sensor for measuring an electrical signal through the skin of the user, for example to measure the resistivity or capacitance of the skin, and thus its moisture content, for example. The sweating can indeed be an indicator of the physical activity and stress of the user.
• A sensor capable of analyzing the sweat of the user, for example in order to measure the amount of sweat or its composition, for example the blood glucose level and / or the presence of hormones or stress-indicating proteins such as cortisone , adrenaline, norepinephrine, dopamine or other hormones or proteins. This sensor can be based for example on a microfluidic wafer capable of providing sweat samples to receptors by capillarity.
• A sensor measuring the testosterone level on the skin of the user, as an indicator of activity.
• One or more environmental sensors for measuring the current time, the current date, the ambient temperature and / or the ambient humidity and / or the ambient brightness and / or the ambient sound level. It is also possible for example to distinguish between different types of sound signals to recognize for example a friendly discussion or an argument, a stressful noise, etc.
• A module retrieving data from the electronic diary and / or from social networks of the user, for example to determine what activities the user is engaged in at different times.
• A brain activity sensor, for example an electroencephalogram detector, capable of distinguishing, for example, whether the brain produces essentially highly periodic α waves, indicating reduced brain activity, or random β waves, indicating more intense brain activity.

Some sensors may be present in the watch or on the case of the watch, for example in its bottom. Some sensors can also be mounted in the bracelet, or in another device worn elsewhere on the body, and connected for example through a wireless link with the watch or the device including the processor. Some sensors can measure data continuously, for example continuously during the measurement of a relative duration, or at regular intervals, for example every second, every minute, etc., or on demand.

The device 1 may also include unrepresented data input means, for example a USB connector or the like, a Bluetooth type radio interface or the like, a touch screen, pushbuttons, etc., allowing the user to access the data. introduce other parameters likely to influence its perception of time. In one embodiment, the user can thus indicate his age, his ethnicity or whether he has consumed alcohol or psychogenic substances.

The device 1 furthermore includes indicators 4 for displaying the current time (ie the absolute time), as well as one or more indicators 5 for displaying the subjective time felt by the user, as it is will see further. The indicator 5 may be for example an analog indicator, for example a pointer, or a digital indicator, for example an alphanumeric indicator or a matrix screen.

A processor 3 makes it possible to receive the measurement signal (s) of the measurement sensor (s), and any data entered by the user or extracted from his diary, in order to process them and to control the indicator 5. In the case of a pointer, the processor 3 can for example control a stepper motor driving the needles. In the case of a matrix trainer, the processor may for example generate still or animated images to be displayed on said screen.

The processor 3 executes a program comprising a software module stored in a computer memory in order to control this indicator to indicate the subjective duration of a time interval, in so that said subjective duration is longer than the effective duration of this interval when said user has the impression that time runs slowly during said interval, and shorter than the effective duration of this interval when said user has the impression that the time flows rapidly during said interval.

The computer module is based on an automatic learning system to determine this subjective duration based on the measurement signals of the various sensors and / or parameters introduced by the user or taken from his agenda or other applications.

In one embodiment, the machine learning system is based on a trained neural network for classifying received measurement signals to determine a perceived duration or subjective rate of time flow.

In another embodiment, the machine learning system is based on support vector machine (SVM) networks trained to classify received measurement signals to determine a perceived duration or subjective velocity. flow of time.

In another embodiment, the machine learning system is based on deep learning algorithms.

In another embodiment, the machine learning system is based on a hidden Markov model (HMMs) or ergodic HMMs to analyze a sequence of successive behaviors.

The learning can be carried out on the basis of measurements made by said sensors and indications introduced by one or more users responsible for labeling durations, and to indicate whether during these periods the time has passed quickly or slowly. Notes or non-binary evaluations may be introduced, for example example to indicate a flow rate of -10 (very slow, the time seems to have stopped) to +10 (very fast). The self-learning system receives the subjective indications introduced by a user as well as the measurement data provided by the sensors during the corresponding durations, and thus trains to classify future measurement data.

The machine learning system can be parameterized before its assembly in the device, independently of the user, for example from measurement signals and data indications felt by a body of users. The training can be performed by asking the users of the corpus to evaluate a subjective duration and then introducing this evaluation and the corresponding measured parameters into the machine learning system.

The machine learning system can also be individually parameterized to each user, for example during an explicit enrollment sequence during which the user indicates the duration of different periods during which measurements have been taken. taken by means of the sensors. It can also be parameterized in use by means of a retropertinence loop, for example of indications of durations felt by the user, or corrections of the estimates displayed by the device 1. In this way, machine learning displays from the same signals a different subjective duration for different users.

The perceived subjective duration can for example be displayed analogically by means of needles 5, similarly to the chronograph hands, in order to display a duration felt since the triggering of the measurement by means of a pushbutton by example, or from another determined moment.

It is also possible to indicate by means of a single pointer or other indicator whether the current rate of time flow is slower or faster than the objective speed.

It is also possible to display with an indicator the degree of satisfaction associated by the user with a duration or a measured time. This degree of satisfaction can be determined by measuring endogenous parameters.

In one embodiment, the subjective duration is displayed on a matrix display, for example in the form of digital data, or with any other representation, for example in the form of an animated film. For example, a horse could be displayed at a gallop when the weather seems to be spinning quickly, and a slower animal when the weather is quiet. The choice of film may depend on the rate of flow during a subjective period entirely in the past, or a subjective period continuing in the present; in this case, the film may represent the rate of flow of time just before the present moment.

Elements of the film or the matrix display, for example a landscape, a choice of character, a decoration, a symbol, etc., could also represent the degree of satisfaction or well-being of the user at any moment or during a measured subjective duration.

The sensory decryption also makes it possible to go from a descriptive time to a prospective time or even indirectly prescriptive time; the user is then led to co-construct the future of his memory and to measure his temporal ecosystem by a comparative operation. In addition to the use of a classic watch that offers a supplementary function of memory, an individual mental temporal reading is added. A user can then for example predict the subjective time that will be necessary for him to complete or finish a given task. The watch may also include a countdown indicator of the subjective time required to complete a given task.

• Réception d'au moins un signal de mesure généré au moyen d'un ou plusieurs capteurs;
• Traitement du signal de mesure au moyen d'un système d'apprentissage automatique afin de déterminer une durée subjective sur la base dudit au moins un signal de mesure, en sorte que la durée subjective soit plus longue que la durée effective de cet intervalle lorsque l'utilisateur a l'impression que le temps s'écoule lentement pendant cet intervalle, et plus courte que la durée effective de cet intervalle lorsque l'utilisateur a l'impression que le temps s'écoule rapidement pendant cet intervalle,
• Affichage de cette durée.

The present invention also relates to a computer data medium including a computer program executable by a processor for determining and displaying a subjective duration perceived by a user, so that the processor performs the following operations:

• Receiving at least one measurement signal generated by means of one or more sensors;
• Processing of the measurement signal by means of an automatic learning system to determine a subjective duration on the basis of said at least one measurement signal, so that the subjective duration is longer than the actual duration of this interval when the the user feels that the time is running slowly during this interval, and shorter than the actual duration of this interval when the user feels that the time is running rapidly during this interval,
• Display of this duration.

This computer program may for example be intended to be executed by an electronic watch, for example a connected watch, or by a smart mobile phone.

Claims (15)

Device (1) portable on the body for determining and displaying a subjective duration perceived by a user, comprising: one or more sensors (2) generating at least one measurement signal, an indicator (5) for representing a duration; a processor (3) processing said measurement signal and controlling said indicator, a computer memory storing a computer module executable by said processor to control said indicator (5) to indicate the subjective duration of a time interval, such that said subjective duration is longer than the effective duration of said interval when said user has the impression that the time runs slowly during said interval, and shorter than the effective duration of this interval when said user has the impression that the time runs rapidly during said interval, said computer module being based on an automatic learning system for determining said subjective duration on the basis of said at least one measurement signal. Device according to claim 1, said automatic learning system being arranged to determine from the same signals a different subjective duration for different users,
said machine learning system being individually drivable to the user by means of a retropertinence loop, for example subjective durations introduced or corrected by the user. Device according to one of claims 1 to 2, said automatic learning system being driven with indications of subjective durations provided by a corpus of several users. Device according to one of claims 1 to 3, said automatic learning system being based on a neural network, on a hidden Markov model or on a carrier vector machine. Device according to one of claims 1 to 4, at least one said sensor being an inertial sensor, the processor being programmed to determine said subjective duration taking into account the movements of said user. Device according to one of claims 1 to 5, at least one said sensor being a temperature sensor, the processor being programmed to determine said subjective duration taking into account the body temperature of said user. Device according to one of claims 1 to 6, at least one said sensor being arranged to measure an electrical quantity linked to an electrical signal through the skin of said user, the processor being programmed to determine said subjective duration taking into account said magnitude electric. Device according to one of claims 1 to 7, at least one said sensor being arranged to measure sweat on the skin of said user, the processor being programmed to determine said subjective duration taking into account said sweat. Device according to one of claims 1 to 8, at least one said sensor being arranged to measure the level of a hormone or protein on the skin of said user, the processor being programmed to determine said subjective duration taking into account said rate of hormone or protein. Device according to one of claims 1 to 1, at least one said sensor being arranged to measure ambient temperature and / or ambient humidity and / or ambient brightness, the processor being programmed to determine said subjective duration taking into account the ambient temperature and / or the ambient humidity and / or the ambient brightness. Device according to one of claims 1 to 10, said processor being programmed to determine said subjective duration taking into account events entered in a calendar of the user. Device according to one of claims 1 to 11, said computer module executable by said processor for controlling an indicator to indicate a degree of satisfaction of said user during said time interval. Device according to one of claims 1 to 12, consisting of a wristwatch. A method for determining and displaying a perceived subjective duration by a user, comprising: Generating at least one measurement signal by means of one or more sensors in a portable device; Processing said measurement signal by means of a processor, said processor executing a computer module based on an automatic learning system to determine a subjective duration based on said at least one measurement signal, so that said subjective duration is longer than the effective duration of this interval when said user has the impression that the time is running slowly during said interval, and shorter than the actual duration of this interval when said user has the impression that time is running out quickly during said interval, displaying said duration. A computer data medium including a computer program executable by a processor for determining and displaying a subjective duration perceived by a user, so that the processor performs the following operations: Receiving at least one measurement signal generated by means of one or more sensors; Processing said measurement signal by means of the automatic learning system to determine a subjective duration based on said at least one measurement signal, such that said subjective duration is longer than the effective duration of said interval when said user has feeling that time runs slowly during said interval, and shorter than the effective duration of that interval when said user has the impression that time passes rapidly during said interval, Display of said duration.

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